This project is now getting to its important stages. We have purified both normal alpha-1-PI (type MM) and the homozygous deficient form (type ZZ) and we are currently comparing their properties which appear to be exclusively in the carbohydrate side chain. Sequencing of both the side chains and the protein, itself, are currently under investigation. The mechanism by which alpha-1-PI interacts with proteases has now begun using human trypsin as a model protease. Our evidence indicates about 2:1 binding of the enzyme to the inhibitor (ref. 6). We are trying to find out just how this interaction occurs. We have now purified a single form of granulocytic elastase by affinity chromatography and we are investigating its properties. We plan to prepare fluorescent antibodies to this protein to find out whether this enzyme is responsible for lung damage in type ZZ individuals. We have also begun a project to investigate the proteases in lung macrophages since they also, presumably, may secrete proteases capable of digesting lung alucolar protein. We hope to eventually study the mechanism by which alpha-1-PI inhibits granulocytic and macrophage elastase and to devise inhibitors to these enzymes which might substitute for alpha-1-PI in vivo.